The Thermal Mass and Buoyancy Ventilation Research Project (TMBV) graduate students have concluded their work and time in Newbern, AL. In their wake, they leave a published, peer-reviewed paper and two research-ready buildings.
In the course of their graduate year, the TMBV project dove deep into the results of their initial small-scale experiments, culminating in a research paper published in the Journal of Physics: Conference Series as a part of the 2021 CISBAT Hybrid Scientific Conference. At the same time, the team designed and constructed two Test Buildings. The cooling and ventilation effects spurred by the optimized thermal mass will be studied throughout the next year, providing ground truth data for the system at a building scale.
The paper: A synopsis
The open-access research paper entitled, “Synchronized coupling of thermal mass and buoyancy ventilation: wood versus concrete” was published in November 2020 in the Journal of Physics Conference: Series. This was an effort involving the entire TMBV research team including Salmaan Craig, Remy Fortin, Sebastien Asselin, Kiel Moe, David Kennedy, and Andrew Freear. The paper describes small-scale experiments that test the accuracy of sizing parameters which suggest how to optimize the coupling of an internal thermal mass—which allows a building to store heat and thereby avoid major temperature fluctuations—with natural ventilation cycles, regardless of the material or the scale of the building. The results suggest the sizing parameters may be valid for early-stage design. They also show that biomaterials, such as wood, can perform as well as conventional thermal mass materials, such as concrete.
Why is this important? Typical, mechanical thermal comfort systems pump greenhouse gases into the atmosphere, raising the temperature even more. They also cannot perform in power outages during weather events caused by the ongoing climate crisis. Therefore, using regenerative materials, such as wood, to mitigate rising temperatures without reliance on the power grid suggests sustainable thermal comfort with less burden on the environment. That is an ongoing aim of the TMBV Research Project, and these initial results are an encouraging step. Before such lofty goals can be reached, the TMBV Test Buildings will provide more insight into the capabilities of the system.
The buildings: A summary
As stated above, the TMBV Test Buildings examine the coupling of thermal mass and buoyancy ventilation as a reliable thermal comfort system at the building scale. Currently, the buildings are set up for these first large-scale experiments and will later be fitted out for housing. The buildings are designed to be flexible spaces for ongoing experiments as well as dwellings for 3rd-year students. Therefore, the buildings balance valid experimental conditions, the realities of construction, and the basic needs of college students. One Test Building is powered by a plywood internal thermal mass and the other by concrete. Both buildings are designed to achieve the same performance parameters for temperature dampening and ventilation rate despite their material differences—i.e., the surface area and thickness of the material.
The buildings are the first Rural Studio buildings constructed primarily out of Structurally Insulated Panels (SIPs). Towering over the Supershed on Morrisette Campus they hover 8′ off the ground. Underneath the buildings is a gathering space nicknamed the “Cooling Porch.” During the day it is meant to collect cool air flowing out of the buildings, providing a place to enjoy the systems en masse. Air travels here through the extended chimneys, which increase ventilation speed and denote the building’s function.
With such tight buildings, dependent on accuracy, the team showed out on all the details. From three-week welding sessions to mapping out patterns of old sidewalk scrap to calculating the discharge coefficient of rooftop vent caps, this team investigated every inch. Feel free to peruse the TMBV blog to see the process, but for now here are the results.
The team: An abridgement
What a journey! These kids, ready to learn how to craft a beautiful building, were not expecting a crash course in thermodynamics, experimental design, and scientific discourse. It was an incredible opportunity to do both. Blending design, construction, and scientific rigor was an extremely unique and fulfilling educational experience. And the TMBV team sharing that experience across North America!
Rowe, the TMBV team’s certified best and most patient construction instructor, has moved to Bozeman, Montana, to join Love | Schack Architecture.
Jeff, a master of power tools and 3D modeling, is taking time to further his coding and woodworking skills.
Cory, a most relaxed, renaissance man, is enjoying his stint at the Ghost Residency with MacKay-Lyons Sweetapple Architects Limited, in Lunenburg, Nova Scotia.
Livia, the heart and volume of the operation, has settled in Austin, Texas, working with Rural Studio Alums at Thoughtbarn.
A huge thank you to the faculty and staff of Auburn University Rural Studio, the teams’ student colleagues, the project consultants (including Joe Farruggia!), the donors and teachers of Turnipseed International, and “Crane” Shane of Sweetwater Construction LLC for your time, knowledge, and support. Most obviously and ardently, thank you to the TMBV research conglomerate Salmaan Craig, Andrew Freear, Steve Long, David Kennedy, Kiel Moe, Sebastien Asselin, and Remy Fortin for the stellar work and dedication. It took a village!
This lot loves Rural Studio and all of its people. Hope to see y’all soon.